Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when it's possible to plant tritoma by checking out the USDA zone info for Portland.

Planting Calendar for Tritoma

Frost tolerance for tritoma:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant tritoma quite a bit earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant tritoma in Portland is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant tritoma and expect a good harvest is probably September. You probably don't want to wait any later than that or else your tritoma may not have a chance to grow to maturity. You can get started a little bit earlier by starting your tritoma indoors.

Last Frost Date

The average date of last frost is March 15 in Portland. In the coldest months of winter you should expect an average low temperature of 15°F.

Since the USDA zone info for Portland is an average the actual date of last frost is different every year. Since half of the time in Portland you get a frost after March 15 be ready to protect your tritoma in the event of a late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Portland

You may be interested in your other planting guides for Portland.